What pattern is there in the power of 3

Answer this question! 30 points and brainliest! only if you know the answer.

Graph red beads cost $1 an ounce and gold beads cost $3 an ounce. juanita wants to purchase a 12-ounce mixture of red and gold beads that she can sell for $2 an ounce. the solution of the system shows the number of beads needed for juanita to break even. x + y = 12, x + 3y = 24 how many ounces of red beads will juanita buy to break even? how many ounces of gold beads will she buy?

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?